Voltage Source (Opt 309) - Agilent Technologies FieldFox N9913A User Manual

Hold-over mode
When the GPS signal is lost, the last GPS reading is used as a hold-over
correction value for the internal reference. The hold-over correction value is no
longer used, but instead the factory-set correction value is used, when any of the
following occur:
Frequency Reference Status
When switched to Ext or GPS, one of the following annotations appears in the
lower-left corner of the screen:



If the FieldFox does NOT find an appropriate Ext or GPS reference signal, then
Ext Ref UNLOCKED
This can occur when any of the following conditions exist:
 NO reference signal is present.
 A low or very high-level external reference signal is present. For best results,
 The external reference is off-frequency.
To learn the expected measurement accuracy when connected to a frequency
reference source, see the FieldFox specifications on page 214.
Reference OUT
The internal 10 MHz frequency reference is available from the Ref/Trig output
connector on the right-side panel. Use this signal as a common frequency
reference when making measurements using external equipment. See this
connector on page 17.
Voltage Source (Opt. 309)
An internal DC source, available with Opt. 309, may be used to provide power for
external devices. The maximum power available is 8 watts.
182
Int
Internal frequency reference
o
Ext
External frequency reference. Connect the 10 MHz External Reference to
o
the Ref In/Trig In SMA (f) connector on the FieldFox top panel. The
FieldFox may take up to 10 seconds to lock to a valid External Reference
source.
GPS
Available ONLY with Built-in GPS (Opt. 307). When selected, the
o
internal GPS is immediately enabled and a search for satellites begins. When
satellites are found, the precision timing signal is NOT used directly, but is
used to correct the absolute frequency of the internal reference many times
per second.
when GPS is disabled.
o
when Reference Source is set to Internal.
o
when the FieldFox resumes from Stand By mode or shut down.
o
EXT R
– External reference is selected.
GPS R
– GPS reference is selected.
GPS H
– Internal Reference is used with last 'hold-over' correction reading.
is displayed in the lower-left corner of the graticule area.
the signal should be between –5 dBm and +5 dBm.
FieldFox User's Guide